I want to use inotifywait to run code upon the creation of a file with a known fixed filename. This answer correctly explains that I cannot run inotifywait directly against a file that does not yet exist and that instead, I should run inotifywait against the parent directory, with an include argument that contains a suitable regex to match the specified filename. If I use the regular expression that that answer suggests, however, I find that other filenames match:
inotifywait -m -e close_write --format %f --include 'hello\.txt' .
# (Then, in another terminal...)
touch hello.txt # Prints hello.txt - this is good.
touch ahello.txt # Prints ahello.txt - this is bad.
touch hello.txta # Prints hello.txta - this is bad.
touch ahello.txta # Prints ahello.txta - this is bad.
"That's easy to fix", I say to myself. "I'll just add in the usual metacharacters to mark the start and end of the string."
inotifywait -m -e close_write --format %f --include '^hello\.txt$' .
# (Then, in another terminal...)
touch ahello.txta # Prints nothing - this is good.
touch ahello.txt # Prints nothing - this is good.
touch hello.txta # Prints nothing - this is good.
touch hello.txt # Prints nothing - this is bad.
man inotifywait clearly states --include <pattern> will "process events only for the subset of files whose filenames match the specified POSIX regular expression, case sensitive." and I can see the filenames (as inotifywait sees them) printed in the first block of code above: when I typed in touch hello.txt, inotifywait printed hello.txt so I know that inotifywait thinks that the filename is hello.txt.
Why is my regular expression ^hello\.txt$ not matching the filename hello.txt? What should I be using instead?
